This invention relates to an excavating tooth point and, more particularly, one advantageously employed on large dragline buckets where the teeth are of substantial size.
For over a century, excavating teeth have been provided in two parts, viz., an adapter attached to the excavator, dragline bucket, shovel dipper, etc., and a replaceable point. It has been the experience of operators of excavating equipment that from 5 to 30 points can be used before a given adapter is worn to the extent of needing replacement. The easy replaceability of points is important because it provides a renewed, sharp penetrating edge, minimizes the amount of throw-away metal, and also minimizes down time--the latter being an especially economic factor with large excavating machinery--see, for example, co-owned U.S. Pat. No. 4,716,668 and 4,727,663.
There have been many locking concepts developed for two-part tooth systems over the years with varying degrees of success in regard to reliability, and ease of installation and removal. However, none of them were both reliable, and easy to install and remove in all types of applications. This is especially true for the large two-part systems used on large draglines. These systems mostly used side pins and snap rings, or spools and wedges. Side pins, for example, are seen in co-owned Pat. No. 4,326,348 and are at times extremely difficult to remove because of the impacted fines and the closeness of adjacent teeth. Spool and wedge removal as seen in co-owned Pat. No. 3,121,289 requires the inconvenience of turning a dragline bucket up on its front end to access the wedges so that they can be sledged out. Also, because wedges can eject during service, it is common practice in many installations to tack-weld wedges to their mating spools thereby making wedge removal even more difficult.
The problems of the prior art have been resolved by the instant invention which features a tooth point having a cavity communicating with the upper pin receiving opening of a point and which is adapted to receive a lock engageable with a slot in a vertically extending pin.
Other objects and advantages of the invention may be seen in the details of the ensuing specification.